CN108362412B - Optical fiber laser pressure sensor and pressure measurement method thereof - Google Patents
Optical fiber laser pressure sensor and pressure measurement method thereof Download PDFInfo
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- CN108362412B CN108362412B CN201810379565.3A CN201810379565A CN108362412B CN 108362412 B CN108362412 B CN 108362412B CN 201810379565 A CN201810379565 A CN 201810379565A CN 108362412 B CN108362412 B CN 108362412B
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 72
- 238000000034 method Methods 0.000 title claims abstract description 33
- 238000009530 blood pressure measurement Methods 0.000 title claims abstract description 19
- 239000000835 fiber Substances 0.000 claims abstract description 100
- 230000010363 phase shift Effects 0.000 claims abstract description 65
- 230000035559 beat frequency Effects 0.000 claims abstract description 34
- 238000001228 spectrum Methods 0.000 claims abstract description 32
- 238000005086 pumping Methods 0.000 claims abstract description 6
- 230000005540 biological transmission Effects 0.000 claims description 12
- 239000011521 glass Substances 0.000 claims description 12
- 230000010287 polarization Effects 0.000 claims description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims description 3
- 230000003287 optical effect Effects 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 abstract description 15
- 238000012360 testing method Methods 0.000 abstract description 10
- 230000008859 change Effects 0.000 description 10
- 238000003825 pressing Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
- G01L1/246—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre using integrated gratings, e.g. Bragg gratings
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Abstract
The invention is suitable for the technical field of optical fiber sensing, and provides an optical fiber laser pressure sensor and a pressure measurement method thereof, wherein an active phase-shift optical fiber Bragg grating is utilized to receive a laser source emitted by a pumping laser, and laser is excited, and the excited laser is reversely transmitted to a wavelength division multiplexer and is input to an isolator from one port of the wavelength division multiplexer; the laser is transmitted in a single phase through the isolator, converted into an electric signal through the photoelectric detector and transmitted to the spectrum analyzer; when the spectrum analyzer receives the electric signals, recording and displaying beat frequency information of the laser in real time; the method comprises the steps that pressure is applied to an active phase-shift fiber Bragg grating, beat frequency information on the spectrum analyzer changes, and when pressure testing is carried out, the size of transverse pressure is obtained according to the corresponding relation between the beat frequency information and the transverse pressure value, which is obtained in advance; the pressure measurement method provided by the invention has high sensitivity and low cost.
Description
Technical Field
The invention belongs to the technical field of optical fiber sensing, and particularly relates to an optical fiber laser pressure sensor and a pressure measurement method thereof.
Background
Compared with the traditional semiconductor laser, the fiber laser has the advantages of good fiber coupling, narrow linewidth, wavelength selectivity, high power and the like. Due to the fact that the double refraction is introduced by the factors of the non-uniformity of the optical fiber, ultraviolet irradiation and the like, the two polarization states of the single longitudinal mode laser output by the optical fiber laser are not overlapped. When both polarization modes simultaneously meet the threshold condition, dual-frequency output can be caused, and beat frequency phenomenon can occur. If pressure is transversely applied to the phase shift grating, the two polarization states of the grating are affected, and the beat signal change is further affected.
At present, the method for realizing pressure test in the field of optical fiber sensing mainly adopts wavelength demodulation, and the methods have the defects of low sensitivity, slow response, incapability of measuring low pressure, high price, complex structure and the like.
Disclosure of Invention
The invention provides a fiber laser pressure sensor and a pressure measurement method thereof, which aim to adopt a frequency demodulation method, and the method is high in sensitivity, simple, efficient and low in cost by transversely applying pressure to an active phase shift fiber Bragg grating and detecting the change of beat frequency signals so as to realize pressure sensing.
The invention provides a fiber laser pressure sensor, comprising: the device comprises a pump laser, a wavelength division multiplexer, an active phase shift fiber Bragg grating, an isolator, a photoelectric detector and a spectrum analyzer, wherein the isolator, the photoelectric detector and the spectrum analyzer are sequentially connected;
The wavelength division multiplexer includes: the input end and the second output end are positioned at one side of the wavelength division multiplexer, and the first output end is positioned at the other side of the wavelength division multiplexer; the input end is connected with the output end of the pump laser, the first output end is connected with the input end of the active phase-shift fiber Bragg grating, and the second output end is connected with one end of the isolator;
The pumping laser is used for emitting a laser light source, and the wavelength division multiplexer is used for pumping the laser light source to the active phase-shift fiber Bragg grating; the active phase-shift fiber Bragg grating is used for exciting laser after receiving the laser light source, reversely transmitting the excited laser to the wavelength division multiplexer and inputting the laser to the isolator from a second output end of the wavelength division multiplexer; the isolator is used for transmitting the laser to the photoelectric detector in a unidirectional mode, and the photoelectric detector is used for converting the laser into an electric signal; the spectrum analyzer is used for recording and displaying beat frequency information of the laser in real time when the electric signal is received; and obtaining the transverse pressure on the active phase-shift fiber Bragg grating according to the corresponding relation between the beat frequency information and the transverse pressure value, which is obtained in advance.
Further, the fiber laser pressure sensor further includes: stage, auxiliary fiber and slide;
The auxiliary optical fiber and the active phase-shift optical fiber Bragg grating have the same diameter, the active phase-shift optical fiber Bragg grating and the auxiliary optical fiber are arranged on the objective table in parallel, the glass slide is arranged on the active phase-shift optical fiber Bragg grating and the auxiliary optical fiber, and pressure is applied to the glass slide through a pressure applying module;
The glass slide is a quartz glass sheet.
Further, the fiber laser pressure sensor further includes: the optical fiber clamp is a rotary clamp and is arranged on the optical fiber bracket;
The optical fiber bracket is used for adjusting the height of the active phase shift optical fiber Bragg grating;
the optical fiber clamp is used for clamping the active phase shift optical fiber Bragg grating.
Further, the active phase shift fiber bragg grating is an erbium-doped active phase shift fiber bragg grating, and the wavelength of laser of the erbium-doped active phase shift fiber bragg grating is 1550nm.
Further, the pump laser is a 980nm laser.
Further, the output end of the pump laser is connected with the input end of the wavelength division multiplexer through a first jumper wire, the first output end of the wavelength division multiplexer is connected with the input end of the active phase shift fiber Bragg grating through a second jumper wire, the second output end of the wavelength division multiplexer is connected with one end of the isolator through a third jumper wire, the other end of the isolator is connected with the input end of the photoelectric detector through a fourth jumper wire, and the output end of the photoelectric detector is connected with the spectrum analyzer through a radio frequency cable;
The first jumper allows transmission of laser with 980nm, the second jumper allows transmission of laser with 980nm and 1550nm, the third jumper allows transmission of laser with 1550nm, and the fourth jumper allows transmission of laser with 1550nm.
Further, the isolator is a polarization dependent optical isolator.
Further, the spectrum analyzer is a point-of-care spectrum analyzer or a scan-tuned spectrum analyzer.
The invention also provides a pressure measurement method of the fiber laser pressure sensor, which comprises the following steps:
Step S1, adjusting the active phase shift fiber Bragg grating to a preset sensitive angle;
and S2, applying transverse pressure on the active phase-shifting fiber Bragg grating, reading beat frequency information on the spectrum analyzer, and obtaining the transverse pressure on the active phase-shifting fiber Bragg grating according to the pre-acquired corresponding relation between the beat frequency information and the transverse pressure value under the preset sensitive angle.
Further, the step S1 specifically includes:
S11, adjusting the height of the optical fiber support to enable the active phase-shifting optical fiber Bragg grating to be separated from the horizontal plane of the objective table, and then rotating the optical fiber clamp to rotate the active phase-shifting optical fiber Bragg grating until the active phase-shifting optical fiber Bragg grating is adjusted to a preset sensitive angle;
And step S12, the height of the optical fiber support is adjusted again, so that the active phase-shifting fiber Bragg grating is located at the horizontal plane height of the objective table, and the optical fiber clamp is loosened, so that the active phase-shifting fiber Bragg grating is placed on the objective table.
Compared with the prior art, the invention has the beneficial effects that: the invention provides an optical fiber laser pressure sensor and a pressure measurement method thereof, wherein an active phase-shift optical fiber Bragg grating is utilized to receive a laser source emitted by a pumping laser, and laser is excited, and the excited laser is reversely transmitted to a wavelength division multiplexer and is input to an isolator from one port of the wavelength division multiplexer; the beat frequencies of the laser are different due to the difference of transverse pressure applied to the active phase shift fiber Bragg grating in the transverse direction; the laser is transmitted in a single phase through the isolator, converted into an electric signal through the photoelectric detector and transmitted to the spectrum analyzer; when the spectrum analyzer receives the electric signals, recording and displaying beat frequency information of the laser in real time; according to the corresponding relation between the beat frequency information and the transverse pressure value obtained in advance, the transverse pressure on the active phase shift fiber Bragg grating is obtained; compared with the prior art, the method adopts a frequency demodulation method to transversely apply pressure to the active phase shift fiber Bragg grating, and realizes pressure sensing through the frequency change of beat frequency signals; since the birefringence of the active phase shift fiber Bragg grating is changed by a small transverse pressure, the method has high sensitivity, simplicity, high efficiency and low cost.
Drawings
FIG. 1 is a schematic diagram of a fiber laser pressure sensor according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an apparatus associated with the pressure application area of the fiber laser pressure sensor of FIG. 1;
FIG. 3 is a schematic flow chart of a pressure measurement method of the fiber laser pressure sensor according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of an embodiment of the present invention providing for applying pressure to an active phase-shifted fiber Bragg grating in a particular direction;
FIG. 5a is a schematic diagram of the change of beat signal intensity of the fiber laser pressure sensor according to the embodiment of the present invention under different pressures;
fig. 5b is a schematic diagram of a linear fitting result of a fiber laser pressure sensor according to an embodiment of the present invention corresponding to beat signals under different pressures.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
The sensitivity is not high when the pressure test is performed by using the wavelength demodulation method in the prior art.
In order to solve the technical problems, the invention provides the fiber laser pressure sensor and the pressure measurement method thereof, which adopt a frequency demodulation method to transversely apply pressure to the active phase shift fiber Bragg grating, realize pressure sensing through the frequency change of beat frequency signals and improve the pressure sensing sensitivity.
The following describes a fiber laser pressure sensor provided in the embodiment of the present invention, as shown in fig. 1, including: the pump laser 101, the wavelength division multiplexer 102 and the active phase shift fiber Bragg grating 103, and further comprise an isolator 104, a photoelectric detector 105 and a spectrum analyzer 106 which are sequentially connected;
The wavelength division multiplexer 102 is a three-port wavelength division multiplexer, and includes: the input end b1, the first output end b2 and the second output end b3, wherein the input end b1 and the second output end b3 are positioned on one side of the wavelength division multiplexer, and the first output end b2 is positioned on the other side of the wavelength division multiplexer 102. The output end of the pump laser 101 is connected with the input end of the wavelength division multiplexer 102 through a first jumper wire, the input end c1 of the active phase-shifting fiber Bragg grating 103 is connected with the first output end of the wavelength division multiplexer 102 through a second jumper wire, and one end of the isolator 104 is connected with the second output end b3 of the wavelength division multiplexer 102 through a third jumper wire; the other end of the isolator 104 is connected with the input end of the photoelectric detector 105 through a fourth jumper, and the output end of the photoelectric detector 105 is connected with the spectrum analyzer 106 through a radio frequency cable.
The pump laser 101 is configured to emit a laser light source, and transmit the emitted laser light source as a pump light source to the wavelength division multiplexer 102 through the first jumper; the wavelength division multiplexer 102 is configured to pump the laser light source to the active phase shift fiber bragg grating 103, specifically, the laser light source passing through the wavelength division multiplexer 102 is output from the first output end b2 and enters the active phase shift fiber bragg grating 103 from the input end c1 of the active phase shift fiber bragg grating 103 through the second jumper; the active phase shift fiber bragg grating 103 is configured to, after receiving the laser light source, laser light, where the laser light is reflected, reversely transmitted to the wavelength division multiplexer 102, and input to the isolator 104 from the second output terminal b3 of the wavelength division multiplexer 102. Specifically, the laser light that is reversely transmitted enters the wavelength division multiplexer 102 through the second jumper and the first output terminal b2 of the wavelength division multiplexer 102, and is input to the isolator from the second output terminal b3 of the wavelength division multiplexer 102. The active phase shift fiber bragg grating 103 receives different lateral pressures in the lateral direction, and the beat signal of the lasing light is different. The isolator 104 is used for transmitting the laser light to the photoelectric detector 105 in a unidirectional way, and the photoelectric detector 105 is used for converting the laser light into an electric signal; the spectrum analyzer 106 is configured to record, monitor and display beat frequency information of the laser in real time when the electrical signal is received; and according to the pre-acquired corresponding relation between the beat frequency information and the transverse pressure value, the transverse pressure on the active phase-shift fiber Bragg grating 103 is obtained.
The beat frequency information refers to frequency information of the beat frequency signal; when no pressure is applied to the active phase-shifting fiber bragg grating 103, the spectrum analyzer 106 displays an initial beat frequency information, and the beat frequency information is changed by applying pressure to the active phase-shifting fiber bragg grating 103; by acquiring the correspondence between beat frequency information and the lateral pressure value in advance, then, during actual measurement, the corresponding lateral pressure value can be acquired by reading the beat frequency information on the spectrum analyzer 106 and combining the correspondence.
Specifically, the active phase shift fiber bragg grating 103 provided by the embodiment of the present invention is an erbium-doped active phase shift fiber bragg grating, which may be a low erbium-doped active phase shift fiber bragg grating or a high erbium-doped active phase shift fiber bragg grating, where the wavelength of the laser of the erbium-doped active phase shift fiber bragg grating is 1550nm; in the embodiment of the present invention, the pump laser 101 is a 980nm laser, the isolator 104 is a polarization-dependent optical isolator, the photodetector 105 is a high-speed photodetector, and the spectrum analyzer 106 is an instantaneous spectrum analyzer or a scanning tuning spectrum analyzer.
Specifically, the first jumper provided by the embodiment of the invention only allows the transmission of laser with the wavelength of 980nm, the second jumper only allows the transmission of laser with the wavelengths of 980nm and 1550nm, the third jumper only allows the transmission of laser with the wavelength of 1550nm, and the fourth jumper only allows the transmission of laser with the wavelength of 1550 nm.
It should be noted that, the active phase shift fiber bragg grating 103 is used as a sensing part in the present invention; specifically, by applying lateral pressure to the active phase-shifted fiber bragg grating 103, the applied lateral pressure is detected by the fiber laser pressure sensor.
Specifically, as shown in fig. 2, the fiber laser pressure sensor further includes: a stage 115, an auxiliary optical fiber 114 and a glass slide 113, the stage 115 is a constant temperature stage, the auxiliary optical fiber 114 has the same diameter as the active phase shift fiber bragg grating 103, and is used for horizontally supporting the glass slide 113. Specifically, the active phase-shifting fiber bragg grating 103 and the auxiliary optical fiber 114 are placed on the stage 115 in parallel, the glass slide 113 is a quartz glass sheet, and placed on the active phase-shifting fiber bragg grating 103 and the auxiliary optical fiber 114, and different pressures can be applied to the glass slide 113 through the pressure applying module 112 to realize pressure testing; it should be noted that the pressing module 112 is representative of any object capable of providing pressure.
The glass slide 113 is used to assist in applying pressure to the active phase-shift fiber bragg grating 103. Because if the glass slide 113 is not arranged, the applied pressure directly acts on the active phase-shifting fiber bragg grating 103, on one hand, the stress surface is small (the diameter of the active phase-shifting fiber bragg grating is about 125 um), and the control is not good; on the other hand, the active phase shift fiber bragg grating 103 is cylindrical and the force process moves. In addition, the slide 113 may in fact be replaced by a plate like a slide.
Further, the fiber laser pressure sensor further includes: the optical fiber device comprises an optical fiber bracket and an optical fiber clamp, which are not shown in the figure, wherein the optical fiber clamp is a rotary clamp and is arranged on the optical fiber bracket; the optical fiber support is one of a square support and an A-frame and is used for adjusting the height of the active phase shift optical fiber Bragg grating 103, and the optical fiber clamp is used for clamping the active phase shift optical fiber Bragg grating 103. Specifically, before the fiber laser pressure sensor is used for measurement, the angle of the active phase shift fiber bragg grating 103 needs to be adjusted, the stress directions of the transverse pressure at different angles are different, and the sensitivity is also different.
The following specifically describes a pressure measurement method of the fiber laser pressure sensor according to an embodiment of the present invention, as shown in fig. 3, including:
Step S1, adjusting the active phase shift fiber Bragg grating to a preset sensitive angle;
The following specifically describes a theoretical derivation process of calculating a pressure value according to a beat signal:
according to the change of the beat frequency signal monitored by the spectrum analyzer, the polarization state of the laser can be judged, wherein the beat frequency signal meets the formula:
,(1)
wherein, f x,fy is the frequency corresponding to two mutually perpendicular polarization states; n x,ny is the refractive index corresponding to two mutually perpendicular polarization states, respectively defined as slow and fast axes (n x>ny), as shown in fig. 4; n 0 is the average refractive index, c is the speed of light, B is the laser center wavelength and is referred to as the birefringence. Therefore, the change (intensity, position) of the beat signal can be observed by the spectrum analyzer, and then the magnitude of B can be determined, and the birefringence B is continuously changed along with the application of different pressures F, wherein the following conditions are satisfied:
，(2)
Wherein n 0 is the average effective refractive index of the grating, p 11, p12 is the elasto-optical coefficient of the grating, v p is poisson's ratio, F is transverse pressure, r is the diameter of the grating, and E is the Young's mode field; θ is the angle between the direction of applied pressure F and n x, as shown in fig. 4, where θ=0°, i.e., the direction of applied pressure F is along the n x axis (slow axis); the change in δb causes a change in beat signal, satisfying:
,(3)
Wherein, L is the length of the grating, and Leff is the effective length of the phase shift region; the relationship between the change δb of the beat signal and the applied pressure F, specifically, if the birefringence δb is changed, may be obtained by the formulas (1), (2), and (3), and the value of the applied pressure F may be obtained from the relationship between δb and the applied pressure F, as in the formula (2).
The preparation work performed before the actual pressure test is performed is described in detail below:
Since the sensitivity of pressure in different lateral directions is different when pressure is applied in the lateral direction of the active phase shift fiber bragg grating, the sensitivity of the active phase shift fiber bragg grating in a certain direction needs to be measured before pressure measurement is performed. The specific method comprises the following steps: applying pressure to the active phase shift fiber Bragg grating in a certain transverse direction through a pressure gauge with scales to obtain the relation between a pressure value and a frequency signal and obtain the sensitivity in the pressure applying direction, so that the fiber laser pressure sensor can be used for pressure test; before performing the pressure test, the active phase shift fiber bragg grating needs to be adjusted to the tested pressure application direction.
The embodiment of the invention enumerates the testing process of sensitivity along the N x axis (slow axis), and as shown in fig. 5a-b, the beat frequency signal changes and the linear fitting result of the fiber laser pressure sensor under different pressures, it can be seen that when the pressure F changes from 0N to 2.91N, the beat frequency signal moves to the high frequency direction and drifts from 182.07MHz to 364.37MHz. After linear fitting treatment is carried out on experimental data, the sensitivity of the transverse pressure reaches 61.4 MHz/(N/mm), wherein y=182.07+61.4 x is the corresponding relation between beat frequency information and transverse pressure value in the fitting direction, x represents the transverse pressure value, and y represents the frequency information of the corresponding beat frequency signal. It should be noted that: only the values of the sensitivity along the n x axis (slow axis) are given here, in fact, the direction of application of force, i.e. θ, is changed to take different values, and the same test method is used to obtain the sensitivity to lateral pressure in different directions of application of force.
The step S1 specifically comprises the following steps:
S11, adjusting the height of the optical fiber support to enable the active phase-shifting optical fiber Bragg grating to be separated from the horizontal plane of the objective table, and then rotating the optical fiber clamp to rotate the active phase-shifting optical fiber Bragg grating until the active phase-shifting optical fiber Bragg grating is adjusted to a preset sensitive angle;
And step S12, the height of the optical fiber support is adjusted again, so that the active phase-shifting fiber Bragg grating is located at the horizontal plane height of the objective table, and the optical fiber clamp is loosened, so that the active phase-shifting fiber Bragg grating is placed on the objective table.
And S2, applying transverse pressure on the active phase-shifting fiber Bragg grating, reading beat frequency information on the spectrum analyzer, and obtaining the transverse pressure on the active phase-shifting fiber Bragg grating according to the pre-acquired corresponding relation between the beat frequency information and the transverse pressure value under the preset sensitive angle.
The invention has potential application in the following fields: (1) high-precision low-pressure sensor: the fiber laser pressure sensor provided by the invention tests the pressure by a frequency demodulation method, and has high sensitivity, especially in the aspect of low-pressure sensing; and such fiber laser pressure sensors are easy to manufacture in large quantities. (2) fiber optic hydrophone: the optical fiber laser pressure sensing device can test underwater sound, and the optical fiber hydrophone is expected to be widely applied to underwater anti-spy operations due to the characteristics of special electromagnetic interference resistance, small volume and the like.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (6)
1. A method of pressure measurement for a fiber optic laser pressure sensor, the fiber optic laser pressure sensor comprising: the device comprises a pump laser, a wavelength division multiplexer, an active phase shift fiber Bragg grating, an isolator, a photoelectric detector and a spectrum analyzer, wherein the isolator, the photoelectric detector and the spectrum analyzer are sequentially connected;
The wavelength division multiplexer includes: the input end and the second output end are positioned at one side of the wavelength division multiplexer, and the first output end is positioned at the other side of the wavelength division multiplexer; the input end is connected with the output end of the pump laser, the first output end is connected with the input end of the active phase-shift fiber Bragg grating, and the second output end is connected with one end of the isolator;
the pumping laser is used for emitting a laser light source, and the wavelength division multiplexer is used for pumping the laser light source to the active phase-shift fiber Bragg grating; the active phase-shift fiber Bragg grating is used for exciting laser after receiving the laser light source, reversely transmitting the excited laser to the wavelength division multiplexer and inputting the laser to the isolator from a second output end of the wavelength division multiplexer; the isolator is used for transmitting the laser to the photoelectric detector in a unidirectional mode, and the photoelectric detector is used for converting the laser into an electric signal; the spectrum analyzer is used for recording and displaying beat frequency information of the laser in real time when the electric signal is received; according to the corresponding relation between the beat frequency information and the transverse pressure value obtained in advance, the transverse pressure on the active phase shift fiber Bragg grating is obtained;
The fiber laser pressure sensor further includes: stage, auxiliary fiber and slide;
The auxiliary optical fiber and the active phase-shift optical fiber Bragg grating have the same diameter, the active phase-shift optical fiber Bragg grating and the auxiliary optical fiber are arranged on the objective table in parallel, the glass slide is arranged on the active phase-shift optical fiber Bragg grating and the auxiliary optical fiber, and pressure is applied to the glass slide through a pressure applying module;
The glass slide is a quartz glass sheet;
The fiber laser pressure sensor further includes: the optical fiber clamp is a rotary clamp and is arranged on the optical fiber bracket;
The optical fiber bracket is used for adjusting the height of the active phase shift optical fiber Bragg grating;
The optical fiber clamp is used for clamping the active phase shift optical fiber Bragg grating;
the pressure measurement method comprises the following steps:
Step S1, adjusting the active phase shift fiber Bragg grating to a preset sensitive angle;
S2, applying transverse pressure on the active phase-shifting fiber Bragg grating, reading beat frequency information on the spectrum analyzer, and obtaining the transverse pressure on the active phase-shifting fiber Bragg grating according to the pre-obtained corresponding relation between the beat frequency information and the transverse pressure value under the preset sensitive angle;
The step S1 specifically comprises the following steps:
S11, adjusting the height of the optical fiber support to enable the active phase-shifting optical fiber Bragg grating to be separated from the horizontal plane of the objective table, and then rotating the optical fiber clamp to rotate the active phase-shifting optical fiber Bragg grating until the active phase-shifting optical fiber Bragg grating is adjusted to a preset sensitive angle;
And step S12, the height of the optical fiber support is adjusted again, so that the active phase-shifting fiber Bragg grating is located at the horizontal plane height of the objective table, and the optical fiber clamp is loosened, so that the active phase-shifting fiber Bragg grating is placed on the objective table.
2. The pressure measurement method of claim 1, wherein the active phase shift fiber bragg grating is an erbium-doped active phase shift fiber bragg grating, and the wavelength of the erbium-doped active phase shift fiber bragg grating lasing light is 1550nm.
3. The pressure measurement method of claim 1, wherein the pump laser is a 980nm laser.
4. The pressure measurement method of claim 3, wherein the output end of the pump laser and the input end of the wavelength division multiplexer are connected through a first jumper, the first output end of the wavelength division multiplexer is connected with the input end of the active phase shift fiber Bragg grating through a second jumper, the second output end of the wavelength division multiplexer is connected with one end of the isolator through a third jumper, the other end of the isolator is connected with the input end of the photoelectric detector through a fourth jumper, and the output end of the photoelectric detector is connected with the spectrum analyzer through a radio frequency cable;
The first jumper allows transmission of laser with 980nm, the second jumper allows transmission of laser with 980nm and 1550nm, the third jumper allows transmission of laser with 1550nm, and the fourth jumper allows transmission of laser with 1550nm.
5. The pressure measurement method of claim 1, wherein the isolator is a polarization dependent optical isolator.
6. The pressure measurement method of claim 1, wherein the spectrum analyzer is a point-of-care spectrum analyzer or a scan-tuned spectrum analyzer.
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| WO2019205028A1 (en) * | 2018-04-25 | 2019-10-31 | 深圳大学 | Optical fiber laser pressure sensor and pressure measurement method therefor |
| RU204010U1 (en) * | 2020-12-15 | 2021-05-04 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Казанский национальный исследовательский технический университет им. А.Н. Туполева - КАИ" | FIBER OPTICAL PRESSURE MEASURING DEVICE |
| RU204013U1 (en) * | 2020-12-15 | 2021-05-04 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Казанский национальный исследовательский технический университет им. А.Н. Туполева - КАИ" | FIBER OPTICAL PRESSURE MEASURING DEVICE |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1844856A (en) * | 2006-05-26 | 2006-10-11 | 北京交通大学 | Transverse stress sensing system of photonic crystal fiber written with grating and implementing method thereof |
| CN101793570A (en) * | 2009-10-21 | 2010-08-04 | 南京大学 | Sensing method of optical-fiber Bragg grating laser device |
| CN202083512U (en) * | 2011-03-29 | 2011-12-21 | 浙江大学 | Micro-pressure sensor |
| CN102778324A (en) * | 2012-07-12 | 2012-11-14 | 暨南大学 | Hydraulic sensor based on orthogonal dual-polarization optical fiber laser |
| CN103591970A (en) * | 2013-11-21 | 2014-02-19 | 黑龙江大学 | Frequency division multiplexing device for double-grating optical fiber multi-longitudinal-mode straight cavity laser sensors |
| CN103616649A (en) * | 2013-12-02 | 2014-03-05 | 暨南大学 | Magnetic field sensor sensitivity tuning method based on fiber bragg grating laser |
| CN208171487U (en) * | 2018-04-25 | 2018-11-30 | 深圳大学 | A kind of optical-fiber laser pressure sensor |
-
2018
- 2018-04-25 CN CN201810379565.3A patent/CN108362412B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1844856A (en) * | 2006-05-26 | 2006-10-11 | 北京交通大学 | Transverse stress sensing system of photonic crystal fiber written with grating and implementing method thereof |
| CN101793570A (en) * | 2009-10-21 | 2010-08-04 | 南京大学 | Sensing method of optical-fiber Bragg grating laser device |
| CN202083512U (en) * | 2011-03-29 | 2011-12-21 | 浙江大学 | Micro-pressure sensor |
| CN102778324A (en) * | 2012-07-12 | 2012-11-14 | 暨南大学 | Hydraulic sensor based on orthogonal dual-polarization optical fiber laser |
| CN103591970A (en) * | 2013-11-21 | 2014-02-19 | 黑龙江大学 | Frequency division multiplexing device for double-grating optical fiber multi-longitudinal-mode straight cavity laser sensors |
| CN103616649A (en) * | 2013-12-02 | 2014-03-05 | 暨南大学 | Magnetic field sensor sensitivity tuning method based on fiber bragg grating laser |
| CN208171487U (en) * | 2018-04-25 | 2018-11-30 | 深圳大学 | A kind of optical-fiber laser pressure sensor |
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